A water tank for flushing a commode is customarily controlled by two valves. One is a water level responsive valve often called a ballcock valve or a tank valve, which whenever the water level is below a pre-selected height, remains open until the water level returns to the selected height. Then this valve closes. Classically a float follows the water level and is effective to cause the tank valve to keep the tank full until the water is released. When the contents are released into the commode, the valve opens to refill the tank.
The other valve is commonly called a flush valve. The tank itself has a water outlet with a valve seat, near or in its bottom where the flush valve is fitted. The flush valve is held closed by the pressure of water when the tank is full or filling. When it is lifted off of the seat, it remains open, usually as the consequence of its own buoyancy, until the water level lowers as the consequence of discharging all or most of the water. It then loses its buoyancy and closes on the seat. Then it keeps the outlet closed while the tank is being refilled, and also until it is again lifted off of the seat.
The flush valve is customarily lifted off of the seat by a lever type linkage. An arm inside the tank is tiltably mounted to a shaft which passes through and is journaled in the tank wall. A handle is mounted to the shaft outside the wall. It is turned to tilt the lever. A flexible chain is connected between the lever and the flush valve so that turning the handle tilts the lever upwardly to lift the chain and thereby raise the valve to start a flushing cycle.
The above describes a conventional, widely-used commode flushing system. Its valves have been the subject of literally hundreds of iterations, all of which at one time were thought to be improvements, at least by their inventors. Strangely, relatively little attention has been paid to the linkages that control the tank valve. The above-described pivoted linkage is very popular, especially in homes where the appearance of the lever is aesthetically acceptable, and in places where vandalism is not anticipated.
However, in public installations, vandalism is to be expected wherever there is something on which the vandal can get a grip. A handle seems to be an enticement to such people. Accordingly, flush systems in public installations are frequently fitted with push buttons that do not project from their surrounding surfaces far enough readily to be grabbed and destroyed, and are circular so they cannot readily be twisted. The problem here is that push button actuators have not previously been suitable for tank type installations. Instead, they have generally been associated with pressure-balanced flush valves which control the flow of water directly from the water supply line to the using commode bowl or urinal. These valves tend to be much more expensive. They do eliminate the tank, but when a tank is acceptable, they are unsuitable even though they enable a push button to be used instead of a handle. A potential disadvantage to any lever type linkage is that there are numerous relative orientations of the handle relative to the tank wall and to the flush valve, and a specific actuating linkage is needed for each. This is a manufacturing and warehousing disadvantage. This is no problem for the push button valve that directly controls the flow of water in the pipe, but that is not a tank type installation. The problem is as serious for push-button linkage as for rotating linkages, and as a consequence, the advantages of a push-button actuation for a tank valve have not been significantly utilized.
It is an object of this invention to provide a tiltable linkage that is able to be rotated around a plurality of axes by actuation of a single push rod. Then a single device can be used for a wide range of tank applications.